Old Second Bancorp, Inc.
US ˙ NasdaqGS ˙ US6802771005

SecurityOSBC / Old Second Bancorp, Inc.
InstitutionQuantinno Capital Management LP
Latest Disclosed Ownership49,879 shares
Latest Disclosed Value $ 1,005,563
Quantinno Capital Management LP reports 58.76% increase in ownership of OSBC / Old Second Bancorp, Inc.

On May 15, 2026 - Quantinno Capital Management LP filed a 13F-HR form disclosing ownership of 49,879 shares of Old Second Bancorp, Inc. (US:OSBC) valued at $1,005,561 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 31,418 shares of Old Second Bancorp, Inc.. This represents a change in shares of 58.76% during the quarter. The current value of the position is $1,068,408 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F OLD SECOND BANCORP INC DEL COM 680277100 49,879 18,461 58.76 1,006 64.22 0.0017
2026-02-17 2025-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 31,418 7,315 30.35 613 47.12 0.0012
2025-11-14 2025-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 24,103 8,439 53.88 417 50.18 0.0011
2025-08-14 2025-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 15,664 15,664 278 0.0012
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.